This is an application for an NIH Pathway to Independence PI Award (K99/R00), entitled Brain systems underlying episodic memory for social stimuli in childhood autism. The overall goal of the proposed research is to understand the neural basis of aberrant episodic memory for social stimuli in children with autism spectrum disorders (ASD). ASD is a neurodevelopmental disorder characterized by life-long deficits in social interactions. Impaired episodic memory for events of social relevance has also been commonly seen in individuals with ASD and such impairments can be highly detrimental to successful social interactions and the formation of long-term social relationships. Understanding aberrant episodic memory, particularly as it pertains to social stimuli, has the potential to provie new insights into the nature and etiology of the disorder. The candidate will use state-of-the-art functional and diffusion tensor brain imaging in conjunction with novel memory paradigms and multivariate methods to compare the neural correlates of episodic memory for social and nonsocial stimuli in children with ASD and typically developing children matched on age, gender and IQ. Memory encoding, retrieval and consolidation processes will be examined. The Specific Aims are: (1) To investigate atypical brain systems underlying episodic memory encoding and retrieval for social stimuli in children with ASD (K99 phase); (2) To investigate atypical brain connectivity underlying episodic memory encoding and retrieval in children with ASD (K99 and R00 phases); (3) To investigate atypical brain systems and connectivity underlying episodic memory consolidation (i.e., long-term retention of memories for social stimuli after several days) in children with ASD, and to determine which memory processes and brain measures are the most reliable predictors of clinical and neuropsychological assessments of memory functioning and social deficits in children with ASD (R00 phase). Findings from this research will advance our understanding of the brain basis of episodic memory dysfunction and its contribution to social deficits in ASD. This knowledge will inform early intervention and remedial education in children with ASD. The candidate will undergo a rigorous education, training, and career development plan in the K99 phase to increase expertise in clinical aspects of ASD research, and multivariate pattern classification analysis of functional brain imaging data in conjunction with structural diffusion tensor imaging. The candidate will be mentored and trained by leading experts in clinical psychology, psychiatry, developmental and cognitive neuroscience, and will gain critical experience in clinical assessments necessary for successfully working with children with ASD. This knowledge and skills during the K99 phase will enable the candidate to become an independent investigator and accomplish the follow-up innovative studies in the R00 phase. Accomplishing the proposed research in the two phases will allow the candidate to launch a rigorous research program by bridging clinical and cognitive neuroscience, and autism research, leading to a competitive NIH R01 grant.